Folding Type Roller Assembly and Footwear Equipped With Them

ABSTRACT

The present invention provides a shoe having a folding roller assembly which is mounted in a receiving seat formed in an outsole of the shoe. The folding roller assembly includes a frame ( 310 ) which is mounted in the receiving seat, a swing case ( 320 ) which is rotatably coupled to the frame, a turning shaft ( 332 ) which is rotatably inserted into a cylindrical hole of the swing case ( 320 ), a yoke ( 331 ) which is coupled to an end of the turning shaft ( 332 ), and the roller ( 340 ) which is rotatably coupled to the yoke ( 331 ). The folding roller assembly further includes a first locking means which locks the swing case ( 320 ) and the yoke ( 331 ) to the frame ( 310 ) while the roller ( 340 ) is extended to the outside, and second locking means which locks and releases the swing case ( 320 ) to and from the frame ( 310 ).

TECHNICAL FIELD

The present invention relates, in general, to folding roller assembliesand, more particularly, to a folding roller assembly which has a simplestructure and is resistant to impact, thus stably supporting a roller.

Furthermore, the present invention relates to a shoe having a pluralityof folding roller assemblies.

BACKGROUND ART

Generally, to roller-skate, users must have exchanged his/her shoes withseparate roller skates or inline skates. There is inconvenience ofcarrying a separate roller skate or inline skate. In an effort toovercome the problems experienced with the separate roller skate orinline skate, a shoe with a folding roller assembly, which is used as atypical shoe in normal conditions and used as a roller skate or inlineskate, as required, was proposed.

FIG. 1 is a bottom perspective view showing a conventional shoe havingfolding roller assemblies. FIG. 2 is a sectional view schematicallyshowing the operation of the folding roller assembly of FIG. 1. As shownin FIGS. 1 and 2, the conventional shoe includes two folding rollerassemblies which are provided in receiving seats formed in an outsole ofthe shoe. Furthermore, the conventional shoe has a structure such thatthe rollers are extracted to the outside, as required.

Each folding roller assembly 100 includes a frame 110 which is mountedin each of the receiving seats of the outsole of the shoe, and a swingcase 120 which is coupled to the frame 110 and is rotatable outwards,with an inner space defined in the swing case 120. The folding rollerassembly 100 further includes a locking means 130 which locks the swingcase 120 to the frame 110 or releases the swing case 120 from the frame110, and a first bevel gear 140 which is placed in the swing case 120and rotatably coupled to the frame 110 so that the first bevel gear 140is rotated along with the swing case 120. The folding roller assembly100 further includes a support 150 which is rotatably disposed along alongitudinal axis of the swing case 120. The support 150 has a secondbevel gear 151 which is provided at a first end of the support 150 andengages with the first bevel gear 140, and a yoke 152 which is providedat a second end of the support 150. The folding roller assembly 100further includes a roller 160 which is rotatably coupled to the yoke 152of the support 150.

The operation of the conventional roller assembly 100 having theabove-mentioned construction will be explained herein below. First, toextract each roller 160, which has been seated in the receiving seat ofthe outsole, to the outside, a user releases the locking state of thelocking means 130 and pulls the roller 160 outwards. Then, the swingcase 120 is turned outwards, and the first bevel gear 140, which isprovided in an end of the swing case 120, is rotated. Thereby, thesecond bevel gear 151, which engages with the first bevel gear 140, isalso rotated. As a result, the roller 160, which is coupled to the yoke152 of the support 150, is turned in a direction perpendicular to theoutsole of the shoe. Thereby, the use of the roller 160 is allowed.

Conversely, to retract each roller 160 into the receiving seat of theoutsole, the user pushes the swing case 120 towards the outsole. Then,the first bevel gear 140, which is provided in the end of the swing case120, is rotated. Thereby, the second bevel gear 151, which engages withthe first bevel gear 140, is also rotated. As a result, the roller 160,which is coupled to the yoke 152 of the support 150, is turned untilbeing parallel with the outsole and, simultaneously, is retracted intothe receiving seat of the outsole. When the roller 160 is completelyretracted into the receiving seat, the swing case 120 is locked by thelocking means 130, so that the roller 160 maintains the state of beingstably seated in the receiving seat.

However, in the conventional folding roller assembly, the support, towhich impact is directly transferred, is merely connected to the swingcase through the bevel gears without being stably supported. That is,the support is indirectly supported on the swing case by the lockingmeans. Therefore, the conventional folding roller assembly has adisadvantage of structural weakness.

Furthermore, because the conventional folding roller assembly uses thebevel gears as a means for turning the roller in a directionperpendicular to or parallel with the outsole, its structure iscomplicated and, as well, there is a difficult in assembling the foldingroller assembly.

Moreover, in the conventional folding roller assembly, a large torsionalforce due to the weight of the user and the turning motion of the rolleris directly transferred to the support, the bevel gears and a connectionpart of the swing case. Accordingly, there is a probability of damage tothe bevel gears and the connection part of the swing case.

FIG. 3 is an exploded perspective view showing another conventionalfolding roller assembly. As shown in FIG. 3, the folding roller assembly200 includes a frame 210 which is mounted in a receiving seat of anoutsole of a shoe, a swing case 220 which is rotatably coupled to theframe 210 and is elastically biased outwards, and a yoke 230 which isrotatably coupled to the swing case 220. The yoke 230 has a second gear231 which is provided on an outer surface of a proximal end of the yoke230 and engages with a first gear 211, which is provided at apredetermined position on the frame 210. The folding roller assembly 200further includes a roller (not shown) which is rotatably coupled to theyoke 230, and a first locking means 240 which is removably inserted intofirst guide grooves 221, which are formed on sidewalls of the swing case220, or into a second guide groove 232, which is formed at apredetermined position on the yoke 230, so that the first locking means240 locks the roller or releases the roller such that the roller can beturned. The folding roller assembly 200 further includes a secondlocking means 250 which locks the swing case 220 to the frame 210 orreleases the swing case 220 from the frame 210 such that the swing case220 is rotatable with respect to the frame 210.

The operation of the folding roller assembly 200 having theabove-mentioned construction will be explained herein below. First, toextract the roller, which has been placed in the receiving seat of theoutsole, to the outside, a user releases the locking state of the secondlocking means 250. Then, the swing case 220 is turned outwards byelasticity of a spring. Simultaneously, the second gear 231 of the yoke230 is rotated along the first gear 211 of the frame 210. Thus, theroller, which is coupled to the yoke 230, is turned in a directionperpendicular to the outsole. At this time, the first locking means 240is inserted into the second guide groove 232 of the yoke 230. Thereby,the use of the roller is allowed.

Conversely, to retract the roller into the receiving seat of theoutsole, the user pulls the first locking means 240 towards the firstguide grooves 221 of the swing case 220 so as to release the lockingstate of the first locking means 240 which has been inserted in thesecond guide groove 232 of the yoke 230. Thereafter, the user pushes thefirst locking means 240 towards the outsole. Then, the second gear 231of the yoke 230 is rotated along the first gear 211 of the frame 210 sothat the roller, which is coupled to the yoke 230, is turned in adirection parallel with the outsole. Thus, the roller is stably seatedinto the receiving seat of the outsole. As such, when the roller iscompletely retracted into the receiving seat, the swing case 220 islocked by the second locking means 250, so that the roller maintains thestate of being stably placed in the receiving seat.

However, in this folding roller assembly, the yoke, to which impact isdirectly transferred, is merely connected to the swing case withoutbeing stably supported. That is, the yoke is indirectly supported on theswing case by the first locking means. Therefore, the folding rollerassembly has a disadvantage of structural weakness.

Furthermore, because the folding roller assembly uses the gears as ameans for turning the roller in a direction perpendicular to or parallelwith the outsole, its structure is complicated and, as well, there is adifficulty in assembling the folding roller assembly.

Moreover, in the conventional folding roller assembly, only the lockingmeans, which is inserted into the guide grooves, supports a largetorsional force that occurs due to the weight of the user and theturning motion of the roller. Accordingly, there is a probability ofdamage to the gears as well as the related elements.

DISCLOSURE OF INVENTION Technical Problem

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the prior art, and an object of the presentinvention is to provide a folding roller assembly which is mounted in areceiving seat formed in an outsole of a shoe such that a roller isextracted to the outside and retracted into the receiving seat.

Another object of the present invention is to provide a shoe having aplurality of folding roller assemblies.

Technical Solution

In order to accomplish the above object(s), the present inventionprovides a folding roller assembly, which is provided in a receivingseat formed under an outsole of a shoe such that a roller is retractedinto the roller seat and is extended to an outside. The folding rollerassembly includes: a frame mounted in the receiving seat; a swing caserotatably coupled at an end thereof to the frame, with a cylindricalhole formed through the swing case; a turning shaft rotatably insertedinto the cylindrical hole of the swing case; a yoke coupled to an end ofthe turning shaft; a roller rotatably coupled to the yoke; a firstlocking means locking the swing case and the yoke to the frame while theroller is extracted to the outside; and a second locking means lockingthe first locking means and the swing case to the frame or releasing thefirst locking means and the swing case from the frame such that thefirst locking means and the swing case are rotatable with respect to theframe.

The folding roller assembly may further include a turning forcegenerating means provided in the turning shaft, the turning forcegenerating means being coupled at a first end thereof to the turningshaft and coupled at a second end thereof to the swing case, thusproviding a turning force to the turning shaft.

The turning force generating means may comprise a spring, opposite endsof which are fixed in a state in which a turning force is previouslyapplied to the spring, so that, when the roller is retracted into thereceiving seat in parallel, the turning force is stored, and, when theroller is extended to the outside, the roller is turned by the turningforce to a perpendicular state thereof.

The folding roller assembly may further include a turning range limitingmeans provided both on an end of the swing case and on a circumferentialouter surface of an end of the yoke so as to limit a turning range ofthe turning shaft with respect to the swing case.

The turning range limiting means may include a guide groove formed onthe circumferential outer surface of the end of the yoke, and a stopprotrusion provided on the end of the swing case and placed in the guidegroove of the yoke, so that the yoke is turned under a guide of the stopprotrusion of the swing case, and the turning motion of the yoke islimited by opposite stop walls of the guide groove of the yoke.

The first locking means may include: a locking slider fitted over both apart of the swing case and a circumferential outer surface of an end ofthe yoke and coupled to the swing case such that the locking slider iselastically biased towards the yoke and is movable with respect to theswing case within a predetermined range, with locking slots provided onsidewalls of the locking slider; and a pair of locking pins provided oninner surfaces of sidewalls of the frame, so that, when the roller isextracted to the outside, the locking pins are inserted into the lockingslots of the locking slider, thus locking the swing case and the yoke tothe frame.

Advantageous Effects

In the present invention, because a turning shaft is inserted into acylindrical hole of a swing case and is rotatably supported by the swingcase, structural stability is ensured.

Furthermore, a locking slider simultaneously holds both a part of theswing case and a part of a yoke, and a pair of locking pins provided onthe frame is inserted into locking grooves formed in sidewalls of thelocking slider. Therefore, even though a large torsional force due tothe weight of the user and the turning motion of the roller is appliedto the folding roller assembly, the roller is stably supported.

Moreover, the present invention has a simple structure in which theroller is turned only by the elasticity of the spring. As well, thepresent invention is resistant to impact, thus ensuring the stability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom perspective view showing a conventional shoe havingfolding roller assemblies;

FIG. 2 is a sectional view schematically showing the operation of thefolding roller assembly of FIG. 1;

FIG. 3 is an exploded perspective view showing another conventionalfolding roller assembly;

FIG. 4 is an exploded perspective view of a folding roller assembly,according to an embodiment of the present invention;

FIG. 5 is a perspective view showing the assembled folding rollerassembly of FIG. 4;

FIG. 6 is a bottom perspective view showing a shoe to which two foldingroller assemblies of FIG. 4 are mounted;

FIG. 7 is a side sectional view showing the folding roller assemblies ofFIG. 6 which are extended to the outside;

FIG. 8 is a bottom view showing the folding roller assembly of FIG. 7which is retracted into an outsole of the shoe; and

FIG. 9 is a front view of the folding roller assembly of FIG. 7.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a folding roller assembly and a shoe having the sameaccording to an embodiment of the present invention will be described indetail with reference to the attached drawings.

FIG. 4 is an exploded perspective view of the folding roller assembly,according to the embodiment of the present invention. FIG. 5 is aperspective view showing the assembled folding roller assembly of FIG.4.

As shown in FIGS. 4 and 5, the folding roller assembly 300 according tothe embodiment of the present invention includes a frame 310 which ismounted in a receiving seat of an outsole of a shoe, and a swing case320 which is rotatably coupled at a first end thereof to the frame 310and is elastically biased outwards. The folding roller assembly 300further includes a support 330 which is rotatably disposed along alongitudinal axis of the swing case 320 and is rotatably supported at afirst end thereof by the swing case 320, with a yoke 331 coupled to asecond end of the support 330. The folding roller assembly 300 furtherincludes a roller 340 which is rotatably coupled to the yoke 331, and aturning force generating means which is provided in the support 330. Theturning force generating means is coupled at a first end thereof to thesupport 330 and coupled at a second end thereof to the swing case 320,thus providing a turning force to the support 330. The folding rollerassembly 300 further includes a turning range limiting means whichlimits a turning range of the support 330 with respect to the swing case320. The folding roller assembly 300 further includes a first lockingmeans which stably locks the swing case 320 and the yoke 331 to theframe 310 when the yoke 331 is swung to a position at which the roller340 is completely extracted to the outside, and a second locking meanswhich locks the first locking means to the frame 310 or releases thefirst locking means from the frame 310 such that the first locking meansis rotatable with respect to the frame 310.

In this embodiment, the frame 310 has a bottom surface, and oppositesidewalls which are perpendicular to the bottom surface, thus defining aspace having a predetermined size. A plurality of fastening holes isformed through the bottom surface of the frame 310, so that the frame310 is fastened to the outsole of the shoe through the fastening holes.

The swing case 320 has a hexahedron shape through which a cylindricalhole is formed. The cylindrical hole comprises a stepped hole having twodifferent diameters. The swing case 320 is rotatably coupled to thesidewalls of the frame 310 and is elastically biased outwards by aspring 321. In detail, the swing case 320 is locked by the secondlocking means while being placed in the space defined by the frame 310.Furthermore, the swing case 320 is elastically rotated outwards whenbeing released from the second locking means.

The swing case 320 has an elongated hole 322 which is formed througheach of sidewalls of the swing case 320. The elongated holes 322 servesto limit a motion range of a locking slider 360 which will be describedlater herein. A plurality of first guide grooves 323, which guide thefirst locking means, is formed on each of outer surfaces of upper andlower walls of the swing case 320.

The support 330 includes a turning shaft 332 which is rotatably insertedinto the cylindrical hole of the swing case 320 such that an end of theturning shaft 332 protrudes from the first end of the swing case 320 toa predetermined length. The support 330 further includes a retainer ring333 which supports the protruded end of the turning shaft 332 such thatthe turning shaft 332 is rotatable with respect to the swing case 320,and the yoke 331 which is integrally coupled to the turning shaft 332.The roller 340 is rotatably coupled to the yoke 331. Here, an insertionhole is formed in the end of the turning shaft 332, which is opposite tothe yoke 331, along a longitudinal axis of the turning shaft 332 to apredetermined depth. A through hole is formed from an end of theinsertion hole to an outer surface of the turning shaft 332. The turningforce generating means is inserted into the insertion hole of theturning shaft 332. The through hole of the turning shaft 332 is used forfastening the first end of the turning force generating means to theturning shaft 332. A proximal end of the yoke 331 which is coupled tothe turning shaft 332 has the same shape and size as those of acircumferential outline of the swing case 320, so that the first lockingmeans can be fitted over the proximal end of the yoke 331.

In this embodiment, the turning force generating means comprises aspring 350 which is inserted into the insertion hole of the turningshaft 332. Opposite ends of the spring 350 are fixed in a state in whicha turning force is previously applied to the spring 350. That is, whenthe swing case 320 is placed in the space defined by the frame 310 andis locked by the second locking means, the spring 350 stores a turningforce. When the swing case 320 is released from the second lockingmeans, the turning shaft 332 is turned by the turning force of thespring 350. Such spring 350 is fixed at a first end thereof by a firstlocking pin (not shown) which is inserted in the through hole of theturning shaft 332. A second end of the spring 350 protrudes to theoutside from the insertion hole of the turning shaft 332 and is fixed toa second end of the swing case 320 by a second locking pin 351.

Meanwhile, the turning range limiting means includes a second guidegroove 334 which is formed on the circumferential outer surface of theproximal end of the yoke 331, and a stop protrusion 324 which isprovided on the second end of the swing case 320 and placed in thesecond guide groove 334 of the yoke 331. Thus, the turning motion of theyoke 331 is executed under a guide of the stop protrusion 324 of theswing case 320, and is stopped when the stop protrusion 324 of the swingcase 320 comes into contact with one of opposite stop walls of the guidegroove 334 of the yoke 331. Preferably, the second guide groove 334 hasa structure such that, when the roller 340 is in a state of beingparallel or perpendicular to the outsole of the shoe, the swing case 320cannot be rotated any more. Furthermore, it is preferable that thesecond guide groove 334 has a rounded shape for ensuring a smooth guideof the stop protrusion 324 of the swing case 320.

The first locking means includes the locking slider 360 which is fittedover both a part of the swing case 320 and the proximal end of the yoke331. The locking slider 360 is coupled to the swing case 320 such thatthe locking slider 360 is elastically biased towards the yoke 331 and ismovable with respect to the swing case 320 within a predetermined range.Two guide protrusions 361 are provided on inner surfaces of oppositesidewalls of the locking slider 360. Two locking slots 362 are providedon outer surfaces of the sidewalls of the locking slider 360. The firstlocking means further includes a pair of third locking pins 311 whichare provided on inner surfaces of sidewalls of the frame 310, so that,when the roller 340 is extracted to the outside, the third locking pins311 are inserted into the locking slots 362 of the locking slider 360,thus locking both the swing case 320 and the yoke 331 to the frame 310.

The locking slots 362 of the locking slider 360 are formed inprotrusions 363 which are provided on the outer surface of the sidewallsof the locking slider 360. Each locking slot 362 is defined by opening aside of each protrusion 363 and closing an opposite side. Eachprotrusion 363 has upper and lower parts which have different lengthssuch that the third locking pins 311 of the frame 310 are smoothlyinserted into and removed from the locking slots 362 of the lockingslider 360. Thus, if a force is applied to the locking slider 360 in adirection opposite to the yoke 331, the third locking pins 311 areremoved from the locking slots 362. In the above state, if the lockingslider 360 is released, the third locking pins 311 are inserted into thelocking slots 362 of the locking slider 360 by the elasticity of thespring 364. In the embodiment, when the third locking pins 311 areinserted in the locking slots 362 of the locking slider 360, the lockingslider 360 simultaneously surrounds both the second end of the swingcase 320 and the proximal end of the yoke 331, thus locking themtogether.

The spring 364 is inserted into the stepped longitudinal hole of theswing case 320 and is supported by a support ring 365. The guideprotrusions 361, which are provided on the inner surface of the lockingslider 360, are inserted into the elongated holes 322 of the swing case320 while the locking slider 360 is fitted over the swing case 320, sothat the locking slider 360 is connected to the spring 364. That is, thespring 364 is coupled to the guide protrusions 361 of the locking slider360, thus compressing the locking slider 360 towards the yoke 331.Preferably, the locking slider 360 has an uneven upper surface. Thus, itis more convenient for a user when the user pulls the locking slider 360in a direction opposite to the yoke 331 or pushes it towards the outsoleof the shoe.

Meanwhile, the second locking means includes two through holes 312 whichare formed through each sidewall of the frame 310, and a stopper 371which is inserted into one through hole 312 of the first sidewall of theframe 310 and reaches the through hole 312 of the second sidewall of theframe 310. A clamp 372 is provided on a first end of the stopper 371 sothat the clamp 372 is inserted into the remaining through hole 312 ofthe first sidewall of the frame 310 and protrudes to a predeterminedlength towards the space defined by the frame 310. The second lockingmeans further includes a lever 373 which is coupled to a second end ofthe stopper 371 which reaches the through hole 312 of the secondsidewall of the frame 310, and a spring 374 which is fitted over anouter surface of the lever 373 so as to provide elasticity to thestopper 371 such that the clamp 372 of the stopper 371 maintains itsstate of being inserted in the through hole 312 of the first sidewall ofthe frame 310. The second locking means further includes a passinggroove (not shown) which is formed under a lower surface of the lockingslider 360 to allow the stopper 371 to reach the second sidewall of theframe 310 through the passing groove of the locking slider 360.

The clamp 372 of the stopper 371 is hooked to a lower part of thelocking slider 360 such that the swing case 320 cannot be rotated whilethe roller 340 is retracted in the receiving seat of the outsole. Whenthe lever 373 is pushed, the clamp 372 releases the swing case 320.Therefore, an end of the clamp 372 preferably has an inclined surfacefor ensuring smooth locking and unlocking motions. Alternatively, theclamp 372 may be hooked to a lower part of the swing case 320 so as tomaintain the locked state of the swing case 320. Of course, even in thiscase, when the lever 373 is pushed, the swing case 320 is released fromthe clamp 372. As a further alternative, the second locking means mayhave a structure such that the swing case 320 is released from the clamp372 by pulling the lever 373 rather than pushing it.

In the embodiment, a pair of protrusion bars 313 may be provided on endsof the sidewalls of the frame 310. The protrusion bars 313 serve toguide the locking slider 360 such that the locking slider 360 rotatesmore smoothly. As well, the protrusion bars 313 serve to stably supportthe locking slider 360 when the roller 340 is completely extracted tothe outside. Furthermore, a guide tip 335 may be provided at apredetermined position on the yoke 331 so that the guide tip 335 comesinto contact with the protrusion bar 313, thus ensuring a smoothrotation of the support 330.

Hereinafter, a shoe with folding roller assemblies having theabove-mentioned structure according to the present invention will beexplained.

FIG. 6 is a bottom perspective view showing the shoe to which twofolding roller assemblies of FIG. 4 are mounted. FIG. 7 is a sidesectional view showing the folding roller assemblies of FIG. 6 which areextended to the outside. FIG. 8 is a bottom view showing the foldingroller assembly of FIG. 7 which is retracted into an outsole of theshoe. FIG. 9 is a front view of the folding roller assembly shown inFIG. 7.

As shown in FIGS. 6 through 9, the folding roller assembly 300 ismounted in each of receiving seats which are formed at front and rearpositions in the outsole of the shoe. Here, support frames (F) areprovided in the receiving seats of the shoe so as to firmly support thepair of folding roller assemblies, which are spaced apart from eachother by a predetermined distance. Furthermore, an opening is formed ata predetermined position in each frame (F) so that the lever 373 of thefolding roller assembly 300 is exposed through the opening to theoutside.

The folding roller assemblies 300 are mounted to the support frames (F)in a line such that the levers 373 are exposed to the outside boththrough the openings of the frames (F) and through a sidewall of theoutsole of the shoe. Unlike the above-mentioned embodiment, a pluralityof folding roller assemblies 300 may be disposed in a line.

The usage of the shoe having the folding roller assembly according tothe present invention will be explained.

To extend each roller 340, which has been in the receiving seat of theoutsole of the shoe, to the outside, the user releases the locking stateof the second locking means. In other words, the user pushes the lever373, which is exposed through the sidewall of the outsole, so that thelocking slider 360, which has been in the locked state thereof due tothe clamp 373 of the stopper 371, is released. Then, the swing case 320is rotated outwards by the elasticity of the spring 321. Simultaneously,the turning shaft 332 and the yoke 331 are turned by the turning forceof the spring 350 which is provided in the turning shaft 332, so thatthe roller 340 becomes perpendicular to the outsole. At this time, thesecond guide groove 334 of the yoke 331 moves under a guide of the stopprotrusion 324 of the swing case 320 while the turning shaft 332 isturned. When the stop protrusion 324 comes into contact with the stopwall of the second guide groove 334, the turning shaft 332 is not turnedany more. Thus, the roller 340 is positioned perpendicular to theoutsole.

As such, when the roller 340 is perpendicular to the outsole, thelocking slider 360 is moved towards the yoke 331 by the elasticity ofthe spring 364, so that the third locking pins 311 of the frame 310 areinserted into the locking slots 362 of the locking slider 360. At thistime, both the first end of the swing case 320 and the proximal end ofthe yoke 331 are simultaneously fastened by the locking slider 360. Assuch, when the swing case 320 and the yoke 331 are stably fastened tothe frame 310 by the first locking means, the user is allowed toroller-skate using the shoe.

Conversely, to retract each roller 340 into the receiving seat of theoutsole of the shoe, the user pulls the locking slider 360 in adirection opposite to the yoke 331. Then, the third locking pins 311 ofthe frame 310 are removed from the locking slots 362 of the lockingslider 360. Furthermore, the yoke 331 is released from the lockingslider 360. In this state, the user pushes the locking slider 360towards the outsole of the shoe, so that the turning shaft 332 and theyoke 331 are turned in a direction parallel to the outsole. Thereby, aturning force is stored in the spring 350 which is provided in theturning shaft 332. Continuously, when the roller 340 is completelyretracted into the receiving seat, the clamp 372 of the stopper 371 ishooked to the locking slider 360, thus bringing the roller 340 into thelocked state. At this time, the stopper 371, which passes through thesidewalls of the frame 310, is inserted into the insert groove formedunder the lower surface of the locking slider 360. As such, the lockedstate of the roller 340 is not released, so long as the lever 373, whichprotrudes from the sidewall of the outsole, is not pushed. As a result,the roller 340 is stably seated in the receiving seat of the outsole.

1. A folding roller assembly, which is provided in a receiving seatformed under an outsole of a shoe such that a roller is retracted intothe roller seat and is extended to an outside, the folding rollerassembly comprising: a frame mounted in the receiving seat; a swing caserotatably coupled at an end thereof to the frame, with a cylindricalhole formed through the swing case; a turning shaft rotatably insertedinto the cylindrical hole of the swing case; a yoke coupled to an end ofthe turning shaft; a roller rotatably coupled to the yoke; first lockingmeans locking the swing case and the yoke to the frame while the rolleris extracted to the outside; and second locking means locking the firstlocking means and the swing case to the frame or releasing the firstlocking means and the swing case from the frame such that the firstlocking means and the swing case are rotatable with respect to theframe.
 2. The folding roller assembly according to claim 1, furthercomprising: turning force generating means provided in the turningshaft, the turning force generating means being coupled at a first endthereof to the turning shaft and coupled at a second end thereof to theswing case, thus providing a turning force to the turning shaft.
 3. Thefolding roller assembly according to claim 2, wherein the turning forcegenerating means comprises a spring, opposite ends of which are fixed ina state in which a turning force is previously applied to the spring, sothat, when the roller is retracted into the receiving seat in parallel,the turning force is stored, and, when the roller is extended to theoutside, the roller is turned by the turning force to a perpendicularstate thereof.
 4. The folding roller assembly according to claim 1 or 2,further comprising: turning range limiting means provided both on an endof the swing case and on a circumferential outer surface of an end ofthe yoke so as to limit a turning range of the turning shaft withrespect to the swing case.
 5. The folding roller assembly according toclaim 4, wherein the turning range limiting means comprises a guidegroove formed on the circumferential outer surface of the end of theyoke, and a stop protrusion provided on the end of the swing case andplaced in the guide groove of the yoke, so that the yoke is turned undera guide of the stop protrusion of the swing case, and the turning motionof the yoke is limited by opposite stop walls of the guide groove of theyoke.
 6. The folding roller assembly according to claim 1 or 2, whereinthe first locking means comprises: a locking slider fitted over both apart of the swing case and a circumferential outer surface of an end ofthe yoke and coupled to the swing case such that the locking slider iselastically biased towards the yoke and is movable with respect to theswing case within a predetermined range, with locking slots provided onsidewalls of the locking slider; and a pair of locking pins provided oninner surfaces of sidewalls of the frame, so that, when the roller isextracted to the outside, the locking pins are inserted into the lockingslots of the locking slider, thus locking the swing case and the yoke tothe frame.
 7. A shoe comprising a plurality of folding rollerassemblies, which are provided in receiving seats formed under anoutsole of the shoe such that rollers are extracted to an outside andare retracted into the roller seats, wherein each of the folding rollerassemblies comprises: a frame mounted in the receiving seat; a swingcase rotatably coupled at an end thereof to the frame, with acylindrical hole formed through the swing case; a turning shaftrotatably inserted into the cylindrical hole of the swing case; a yokecoupled to an end of the turning shaft; a roller rotatably coupled tothe yoke; first locking means locking the swing case and the yoke to theframe while the roller is extended to the outside; and second lockingmeans locking the first locking means and the swing case to the frame orreleasing the first locking means and the swing case from the frame suchthat the first locking means and the swing case are rotatable withrespect to the frame.
 8. The shoe according to claim 7, wherein each ofthe folding roller assemblies further comprises: turning forcegenerating means provided in the turning shaft, the turning forcegenerating means being coupled at a first end thereof to the turningshaft and coupled at a second end thereof to the swing case, thusproviding a turning force to the turning shaft.
 9. The shoe according toclaim 8, wherein the turning force generating means of each of thefolding roller assemblies comprises a spring, opposite ends of which arefixed in a state in which a turning force is previously applied to thespring, so that, when the roller is retracted into the receiving seat inparallel, the turning force is stored, and, when the roller is extendedto the outside, the roller is turned by the turning force to aperpendicular state thereof.
 10. The shoe according to claim 7 or 8,wherein each of the folding roller assemblies further comprises: turningrange limiting means provided both on an end of the swing case and on acircumferential outer surface of an end of the yoke so as to limit aturning range of the turning shaft with respect to the swing case. 11.The shoe according to claim 10, wherein the turning range limiting meansof each of the folding roller assemblies comprises a guide groove formedon the circumferential outer surface of the end of the yoke, and a stopprotrusion provided on the end of the swing case and placed in the guidegroove of the yoke, so that the yoke is turned under a guide of the stopprotrusion of the swing case, and the turning motion of the yoke islimited by opposite stop walls of the guide groove of the yoke.
 12. Theshoe according to claim 7 or 8, wherein the first locking means of eachof the folding roller assemblies comprises: a locking slider fitted overboth a part of the swing case and a circumferential outer surface of anend of the yoke and coupled to the swing case such that the lockingslider is elastically biased towards the yoke and is movable withrespect to the swing case within a predetermined range, with lockingslots provided on sidewalls of the locking slider; and a pair of lockingpins provided on inner surfaces of sidewalls of the frame, so that, whenthe roller is extracted to the outside, the locking pins are insertedinto the locking slots of the locking slider, thus locking the swingcase and the yoke to the frame.